<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        //1 向body输出内容 标签有用
        document.write("我是div标签")
        document.write("<h1>我是h1标签</h1>")

        //2 alert弹出消息框

        //3 console.log 输出在控制台
        console.log('看看对不对')

    </script>
</body>
</html>